Influence of different mixing ratios on in-vessel co-composting of sewage sludge with horse stable straw bedding waste: maturity and process evaluation.
- Evaluation Study
- Journal Article
Summary
This research article explores the effects of co-composting sewage sludge with horse stable straw bedding waste (HSB) at various ratios, and found that a 1:2.9 ratio had improved organic decomposition and reached maturity quicker than a 1:1.5 ratio.
Experimental Design
In the experiment, sewage sludge was mixed with horse stable straw bedding waste (HSB) at two different ratios – 1:1.5 (HSL) and 1:2.9 (LSL). The mixture was then subjected to a 7-day composting process in a 10 tonnes per day in-vessel composter, followed by curing in a static aeration pile. The composting period lasted for a total of 56 days.
- HSL: This represents the mixture of the sewage sludge with HSB at a ratio of 1:1.5.
- LSL: This represents the mixture of the sewage sludge with HSB at a ratio of 1:2.9.
Findings
The study found that both the LSL and HSL mixing ratios were feasible for the composting process. However, the LSL mixture showed better organic decomposition than the HSL mixture and also reached maturity faster.
- Decomposition Rates: The study recorded overall decomposition rates of 52.0% and 58.9% for HSL and LSL, respectively.
- Temperature: During the experiment, it was noted that temperatures in the in-vessel composters could reach up to 65°C, which is sufficient enough to destroy pathogens.
- Pathogens: Both products (HSL and LSL mixtures) were found to be free of pathogens after the composting process.
However, the HSL mixture had higher ammoniacal nitrogen content than the LSL mixture, and also had a lower seed germination index. This implies that HSL has a higher phytotoxicity, and hence it would require a longer curing time.
Conclusions
The study concluded that horse stable straw bedding waste (HSB) served well as a co-composting material for sewage sludge, specifically at a mixing ratio of 1:2.9. This ratio provided better composting conditions, quicker maturation, and more efficient organic decomposition.
Cite This Article
Publication
Researcher Affiliations
- Sino-Forest Applied Research Centre for Pearl River Delta Environment and Department of Biology, Hong Kong Baptist University, Hong Kong SAR. jwcwong@hkbu.edu.hk
MeSH Terms
- Animal Husbandry / methods
- Animals
- Horses
- Housing, Animal
- Humidity
- Hydrogen-Ion Concentration
- Organic Chemicals / analysis
- Organic Chemicals / chemistry
- Organic Chemicals / metabolism
- Porosity
- Sewage / analysis
- Sewage / chemistry
- Soil Pollutants / analysis
- Soil Pollutants / chemistry
- Soil Pollutants / metabolism
- Temperature
- Time Factors
- Waste Disposal, Fluid / methods
Citations
This article has been cited 3 times.- Sowiński J, Jama-Rodzeńska A, Perera PCD, Jamroz E, Bekier J. The changes of willow biomass characteristics during the composting process and their phytotoxicity effect on Sinapis alba L.. PLoS One 2022;17(10):e0275268.
- Arnone S, De Mei M, Petrazzuolo F, Musmeci S, Tonelli L, Salvicchi A, Defilippo F, Curatolo M, Bonilauri P. Black soldier fly (Hermetia illucens L.) as a high-potential agent for bioconversion of municipal primary sewage sludge.. Environ Sci Pollut Res Int 2022 Sep;29(43):64886-64901.
- Asgari A, Nabizadeh R, Mahvi AH, Nasseri S, Dehghani MH, Nazmara S, Yaghmaeian K. Biodegradation of total petroleum hydrocarbons from acidic sludge produced by re-refinery industries of waste oil using in-vessel composting.. J Environ Health Sci Eng 2017;15:3.
